I just wanted to check in and say thank goodness you are reconsidering this. This question comes up at least once every few months in my CCW class. The blank will lower your capacity by one effective round. That might be the round that saves your life. The person who will not retreat at the sight of a gun will likely not retreat at what he percieves as inaccurate fire. There is no
good reason to do this. If you pull a gun on someone, the requirements for lethal force should already be met, because you are employing lethal force whether the gun is loaded with a blank or not. If you are squeamish about taking a life, then reconsider the whole prospect of owning firearms for self defense. If you are not sqeamish, then use the weapon effectively.